Poisoning Attacks to Graph-Based Recommender Systems

Recommender system is an important component of many web services to help users locate items that match their interests. Several studies showed that recommender systems are vulnerable to poisoning attacks, in which an attacker injects fake data to a recommender system such that the system makes recommendations as the attacker desires. However, these poisoning attacks are either agnostic to recommendation algorithms or optimized to recommender systems (e.g., association-rule-based or matrix-factorization-based recommender systems) that are not graph-based. Like association-rule-based and matrix-factorization-based recommender systems, graph-based recommender system is also deployed in practice, e.g., eBay, Huawei App Store (a big app store in China). However, how to design optimized poisoning attacks for graph-based recommender systems is still an open problem.